1. Field of the Invention
The present invention relates to an indication device in the viewfinder of single lens reflex cameras having a viewfinder optical system comprising a viewfinder element and a viewfinder screen unit removably and exchangeably mounted on the camera body.
2. Description of the Prior Art
Conventionally such an indication device in a viewfinder consists of an informative members unit for indicating information regarding the diaphragm aperture, shutter speed, propriety of exposure and the like, and a reflective member for leading the information into the viewfinder optical system. The informative members unit and the reflective member are placed near or in close proximity to a pentaprism of the viewfinder.
However if the single lens reflex camera has such viewfinder optical system that its viewfinder element and viewfinder screen unit are exchangeable, it is unallowable for reasons of function to build the informative members unit in the viewfinder element or in the viewfinder screen unit.
In this case, the informative members unit must be built in the camera body itself so that the informative members may readily be interlocked with a shutter speed dial, a lens diaphragm or the like associated with the informative members respectively. On the other hand, the reflective member should be arranged in the viewfinder optical system. It is by no means easy to solve the problem in a simple and satisfactory manner.